Vacuum-pump.



No. 859,179. PATBNTED JULY 2, 1907. J. J. MULLAN.

VACUUM PUMP.

mmon um FILED mm. 1905.

JOSEPH J. MULLAN, OF PHILADELPHIA, PENNSYLVANIA.

VACUUM-PUMP.

' Specification of Letters Patent.

Patented July 2, 1907;

Application filed August 4,1905. Serial No. 272,656.

To all whom 'it may concern:

Be it known that I, Josnrn J. MULLAN, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented an Improvement in Vacuum-Pumps, of which the following is a specification.

My invention relates to vacuum pumps and particularly to vertical single acting wet vacuum pumps having valveless inlets, and in carrying out the same Ipreferably employ in connection with a suitable base a cylinder, a casing of greater diameter than said cylinder and extending upwardly therefrom, an internal wall in said casing terminating in a downwardly extending flange of the same interior diameter as that of the said cylinder, a lining fitting within said flange and extending between the same and the said cylinder-and provided with suitable ports or apertures immediately above said cylinder, a piston fitting said lining, a piston-rod therefor, a head for the lower end of said cylinder, a valve plate supported on and secured to said internal wall, discharge valves secured therein, a head for said casing, a suction connection on said casing below the said internal wall, a discharge connection on said casing above the said internal wall, and means for equalizing the pressure on opposite sides of the piston at the beginning of each stroke and for removing or discharging the liquid which may accumulate in the cylinder below said piston due to leakage, all of which will be hereinafter more particularly described.

In the drawing, Figure 1 is an elevation of my improved vacuum pump. Fig. 2 is a central vertical section of the same. Fig. 3 is a plan of the same on a reduced scale, and Fig. 4 is a section on line 0;, a, Fig. 2. In Fig. 2 the piston is shown in the extreme downward position by dotted lines.

Referring to the drawing, a designates a base which may be of any desired shape orof any suitable material, and the same is preferably provided with a seat 2 upon which a flange 3 of a cylinder 6 rests and is suitably secured. 0 represents a casing, preferably concentric with the cylinder b, but of considerably greater diameter and extending upwardly from the same. The casing c is provided interiorly and approximately centrally with the wall (I, and this wall (I terminates in a downwardly extending flange 4 of the same internal diameter as that of the cylinder 1), and a lining e of bronze or other suitable material is fitted into the said flange 4 and extends between the is provided with a head f, the walls of which are preferably conical, and supported upon. the internal wall d and suitably secured thereto is a valve-plate g, in which the discharge .valves h, which may be of any suitable construction, are secured, and the casing c is provided at its upper end with a suitable head 2'. Below the internal wall d the casing c is provided with a suction connection it and above the wall d the casing c is provided with a discharge connection l.

Within the lining a and cylindrical portion 1) is a piston m to which are suitably secured piston-rods n extending through the valve-plate g and head i and through suitable packing glands 0. The lower end of the piston m is provided with conical walls 6, constructed at a slightly smaller angle than the walls of the head f, providing an angular space between the said Walls when the piston is in its extreme lower position and centrally the piston m is provided with a passage.

7 extending longitudinally through the same and in the upper portion of which a check-valve 8 is employed, a suitable valve-seat 9 being provided for the check-valve in the walls of the passage 7, and at the upper end of this passage a perforated stop-plate 10 is employed to limit the movement of the said check-valve.

I also provide a suitable wall, a portion 11 of which extends exteriorly between the lower portion of the easing 0 and the lower end of the cylinder 1), and a portion 12 of which extends interiorly from the upper end of the cylinder to a point adjacent to the edge of the flange 4, whereby a communicating passage 13 is provided between the opposite ends of the piston or, and if desired I may provide the casing c with suitable hand-holes 14 and hand-hole covers 15. It will be readily apparent that the passage 13 provides a means for interiorly connecting the upper and lower sides of the piston, thereby equalizing the pressure on the opposite sides of the same and also that by the difierence in the angle at which the conical walls of the cylinder head and the lower end of the piston are constructed and by the orifice at the lower end of the passage-way 13 being appreciably above the bottom of the lower cylinder head f, that any liquid accumulating below the piston from leakage or any other cause, will be expelled (without force, thereby preventing pounding), through the passage 7 around the check-valve 8 and into the upper end of the cylinder above the piston, it being manifest that this operation in expelling the water by the checkvalve construction will also assist in the function of equalizing the pressure on the opposite sides of the piston, and that that portion 12 of the cylinder providing the passage 13 being extended to the approximate level munication between the opposite sides of the piston is provided at the beginning of every stroke and that this communication when the piston is in its lowermost position is by way of the ports 5 and the passage 13, and when the piston is in its uppermost position is by the passage 7 and the relief valve 8, and further, that by this structure the efficiency of the apparatus is materially increased by reducing the power required to operate the pump.

I claim as my invention:

1. In a single acting vacuum pump having a valveless inlet and in combination, a cylinder, a lining within the cylinder and extending above the same, a casing extending upwardly from the cylinder and of greater diameter than the same so as to form an internal chamber between the said casing and that part of the lining which extends above the cylinder, a piston fitting the said lining, a wall intersecting the said chamber and of a height greater than the diameter of the valveless inlet, the upper end of this wall extending to a point higher than the top of the said valveless inlet and said wall providing a passageway between the said chamber and the opposite end of the piston for equalizing the pressure on opposite sides of the piston.

2. A vacuum pump having a valveless inlet and comprising a base, a cylinder body of varying diameters with an annular chamber in the upper part, a piston which this annular chamber surrounds at the upper part of its stroke, a series of ports in the cylinder body at the base of the annular chamber so placed as to come imme diatcly above the upper end of the piston when at the lower part of its stroke and a wall formed with the said cylinder body and providing a passage-way extending first upwardly and then downwardly between the opposite ends of the same so as to equalize the pressure on the opposite sides of the piston.

3. A vacuum pump having a valveless inlet and comprising a base, a cylinder body of varying diameters with an annular chamber in the upper part and an inwardly extending conical head at the lower end of the said cylinder body, a piston which this annular chamber surrounds at the upper part of its stroke, having a conical wall conforming approximately with the conical head of the cylinder body and having a central longitudinal pas sageway therethrough between the apex of the conical wall and the upper surface of the cylinder, and a relief valve located in the upper end of thesaid passage-way.

4. A vacuum pump having a valveless inlet and comprising a base, a cylinder body of varying diameters with an annular chamber in the upper part and an inwardly extending conical head at the lower end of the said cylinder body, a piston which this annular chamber surrounds at the upper part of its stroke, having a conical wall conforming approximately with the conical head of the cylinder body and having a central longitudinal passage-way therethrough between the apex of the conical wall and the upper surface of the cylinder, a relief valve located in the upper end of the said passage-way and a wall integral with the said cylinder body providing a passage-way communicating at one end with the said annular chamber and at the other end with the lower end of the cylinder so as to equalize the pressure on the opposite sides of the piston.

5. A vacuum pump having a valveless inlet and comprising a base, a cylinder body of varying diameters with an annular chamber in the upper part and an inwardly extending conical head at the lower end of the said cylinder body, a piston which this annular chamber surrounds at the upper part of its stroke, having a conical wall conforming approximately with the conical head of the cylinder body and having a central longitudinal passage-way therethrough between the apex of the conical wall and the upper surface of the cylinder, a relief valve located in the upper end of the said passage-way, a wall integral with the said cylinder body providing a passageway communicating at one end with the said annular chamber, the opening of said passage-way at the lower end into the cylinder terminating appreciably above the bottom of the cylinder.

0. A vacuum pump having a valveless inlet and comprising a base, a cylinder body of varying diameters with an annular chamber in the upper part thereof, a lining within the cylinder body and its annular chamber, a piston movable in said lining and in the lower portion of the cylinder body and which this annular chamber surrounds at the upper part of its stroke, a series of .ports in the lining at the base of the annular chamber so placed as to come immediately above the upper end of the piston when at the lower part of its stroke and a wall formed with the cylinder body and at its upper end opening into the said annular chamber and at its lower end communicating with the lower portion of the cylin der body below the piston, so that the passage-way from said ports to the bottom of the cylinder shall extend first upwardly and then downwardly.

7. A vacuum pump having a valveless inlet and comprising a base, a cylinder body of varying diameters with an annular chamber in the upper part thereof, a lining within the cylinder body and its annular chamber, a piston movable in said lining and in the lower portion of the cylinder body and which this annular chamber surrounds at the upper part of its stroke, a series of ports in the lining at the base of the annular chamber so placed as to come immediately above the upper end of the piston when at the lower part of its stroke and a wall formed with the cylinder body and at its upper end opening into the said annular chamber and at its lower end communicating with the lower portion of the cylinder body below the piston, the opening of this passageway into the cylinder body below the piston being appreciably above the bottom of the cylinder and means located wholly within the movable piston and effectivetoward the lower end of its stroke for removing fluid from beneath the piston.

S. A vacuum pump having a valveless inlet and comprising a base, a cylinder body of varying diameters with an annular chamber in the upper part thereof, a lining within the cylinder body and its annular chamber, a piston movable in said lining and in the lower portion of the cylinder body and which this annular chamber surrounds at the upper part of its stroke, a series of ports in the lining at the base of the annular chamber so placed as to come immediately above the upper end of the piston when at the lower part of its stroke, the lower end of the cylinder body being provided with an in wardly extending conical head and the lower end of the piston with a conical wall slightly offset from exact conformity with the conical head of the cylinder, said divergence being greatest at the apexes of the cones whereby any fluid in the lower end of the cylinder is gradually raised as the conical parts approach one another.

9. A vacuum pump having a valveless inlet and comprising a base, a cylinder body of varying diameters with an annular chamber in the upper part thereof, a lining within the cylinder body and its annular chamber, a piston movable in said lining in the lower portion of the cylinder body and which this annular chamber surrounds at the upper part of its stroke, a series of ports in the lining at the base of the annular chamber so placed as to-come immediately above the upper end of the piston when at the lower part of its stroke, the lower end of the cylinder body being provided with an inwardly extending conical head and the lower end of the piston with a conical wall slightly oft-set from exact conformity with the conical head of the cylinder, said divergence being greatest at the apexes of the cones whereby any fluid in the lower end of the cylinder is gradually raised as the conical parts approach one another, the said piston having a central longi tudinal passage-way therethrough and a relief valve located at the upper end of the passage-way near the upper surface of the piston and means establishing communication between the respective ends of the cylinder and coming at its lower end short of the cylinder bottom.

10. In a single acting vacuum pump having a valveless inlet, the combination with the cylinder and a conical lower head thereto, of a piston having a central passageway and a valve therein opening upward, a conical lower wall to said piston adapted to fit over the conical lower head, but of a greater inclination to the horizontal, so that in the juxtaposed relation of said parts there is an annular space widest at the center and tapering to substantially nothing at the outer edge.

11. A vacuum pump having a valveless inlet and com prising a base, a cylinder, a conical head for the said cylinder, a piston having a conical wall conforming approximately with the conical head of the cylinder and having a central longitudinal passage-way therethrough, a relief valve located at the upper end of said passage way and a wall integral with the said cylinder providing a passage way communicating between the opposite ends thereof, the opening of which at the lower end into the cylinder is appreciably above the bottom of the cylinder.

12. A single acting vacuum pump having a valveless inlot and comprising a base, a cylinder, a casing extending above the cylinder and of greater diameter than the same, a wall extending upwardly within the said casing and a wall extending downwardly from the said casing and exteriorly of the cylinder to the end of the same, said walls providing a passage-way between the respective ends of the cylinder.

- 1: In a single acting vacuum pump having a valveless inlet, the combination with a base and a cylinder supported thereon. of a casing extending upwardly from the cylinder, a lining for the said cylinder, a piston fitting said lining, a head secured to the lower end of the said cylinder. a valve-plate within the said casing, discharge valves therein. a head for the said casing, a suction eonnection leading through said casing and to said cylinder, a discharge connection from said casing, and means providing a passage-way extending first upwardly and then downwardly for equalizing the pressure on opposite sides of the said piston at the beginning of each stroke.

1-l. In a single acting vacuum pump having a valveless inlet, the combination with a base, of a cylinder, a casing of greater diameter than said cylinder connected therewith and extending above the same, an internal wall connected to said casing and terminating in a downwardly projecting flange of the same interior diameter as the said cylinder. a lining fitting said flange and extending between the same and the upper end of said cylinder, a piston, a piston-rod therefor, a head for the lower end of said cylinder. a valve-plate supported by and secured to the said internal wall, discharge valves therein, a head for said casing, a suction connection in said casing below the internal wall thereof. a discharge connection in said casing and above the said internal wall. and means providing a passage-way extending first upwardly and then downwardly for equalizing the pressure on opposite sides of the said piston at the beginning of each stroke.

15. In a single acting vacuum pump having a valveless inlet, the combination with a base, of a cylinder, a casing of greater diameter than said cylinder and integral therewith and extending above the same, an internal wall integral with said casing and terminating in a downwardly projecting flange of the same interior diameter as the said cylinder, a lining fitting within said flange and extending between the said flange and the upper end of said cylinder and provided with a series of ports or apertures immediately above said cylinder, a piston provided at its lower end with a conical wall and a passage extending centrally and longitudinally through the same, a chccl valve located in the upper end of said passage, a perforated stop-plate secured at the upper end of said passage, piston-rods for said piston, a head for the lower end of said cylinder having conical walls made at an angle somewhat less than the said conical walls of the lower end of the piston, a valveplate supported by and secured to the said internal wall, valves therein, a head for the casing, a suction connection in said casing below the said internal wallthereot and communicating with the interior of the said cylinder and lining through the said apertures in the said lining, and a discharge connectionin the casing above the said internal wall.

16. In a single acting vacuum pump having a valveless inlet, the combination with a base, of a cylinder, a casing of greater diameter than said cylinder, integral therewith and extending above the same, an internal wall integral with said casing and terminating in a downwardly projecting flange of the same interior diameter as the said cylinder, a lining fitting within the said flange and extending between the said flange and the upper end of the said cylinder and provided with a series of ports or apertures immediately above said cylinder, a piston provided at its lower end with a conical wall and a passage extending centrally and longitudinally through the same, a check-valve located in the upper end of said passage, a perforated stop-plate secured at the upper end of said passage, piston-rods for said piston, a wall partially within the said casing and partially without the said casing providing a communicating passage between the upper and lower ends of the said piston a head for -the lower end of said cylinder having conical walls made at an angle somewhat less than the said conical walls of the lower end of the piston, a valve-plate supported by and secured to the said internal wall, valves therein, a head for the casing, a suction connection in said casing below the said internal wall thereof and communicating with the interior of the said cylinder and lining through the said apertures in the said lining, and a discharge connection in the casing above the said internal wall;

Signed by me this twenty sixth day of July 1905.

JOSEPH J. MULLAN.

Witnesses ItonNnx MORRISON, WM. B. SoNDnn. 

